
/*
 * Copyright (C) Igor Sysoev
 * Copyright (C) Nginx, Inc.
 */


#include <ngx_config.h>
#include <ngx_core.h>
#include <ngx_http.h>


static void ngx_http_init_request(ngx_event_t *ev);
static void ngx_http_process_request_line(ngx_event_t *rev);
static void ngx_http_process_request_headers(ngx_event_t *rev);
static ssize_t ngx_http_read_request_header(ngx_http_request_t *r);
static ngx_int_t ngx_http_alloc_large_header_buffer(ngx_http_request_t *r,
                                                    ngx_uint_t request_line);

static ngx_int_t ngx_http_process_header_line(ngx_http_request_t *r,
                                              ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_process_unique_header_line(ngx_http_request_t *r,
                                                     ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_process_host(ngx_http_request_t *r,
                                       ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_process_connection(ngx_http_request_t *r,
                                             ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_process_user_agent(ngx_http_request_t *r,
                                             ngx_table_elt_t *h, ngx_uint_t offset);
static ngx_int_t ngx_http_process_cookie(ngx_http_request_t *r,
                                         ngx_table_elt_t *h, ngx_uint_t offset);

static ngx_int_t ngx_http_process_request_header(ngx_http_request_t *r);
static void ngx_http_process_request(ngx_http_request_t *r);
static ssize_t ngx_http_validate_host(ngx_http_request_t *r, u_char **host,
                                      size_t len, ngx_uint_t alloc);
static ngx_int_t ngx_http_find_virtual_server(ngx_http_request_t *r,
                                              u_char *host, size_t len);

static void ngx_http_request_handler(ngx_event_t *ev);
static void ngx_http_terminate_request(ngx_http_request_t *r, ngx_int_t rc);
static void ngx_http_terminate_handler(ngx_http_request_t *r);
static void ngx_http_finalize_connection(ngx_http_request_t *r);
static ngx_int_t ngx_http_set_write_handler(ngx_http_request_t *r);
static void ngx_http_writer(ngx_http_request_t *r);
static void ngx_http_request_finalizer(ngx_http_request_t *r);

static void ngx_http_set_keepalive(ngx_http_request_t *r);
static void ngx_http_keepalive_handler(ngx_event_t *ev);
static void ngx_http_set_lingering_close(ngx_http_request_t *r);
static void ngx_http_lingering_close_handler(ngx_event_t *ev);
static ngx_int_t ngx_http_post_action(ngx_http_request_t *r);
static void ngx_http_close_request(ngx_http_request_t *r, ngx_int_t error);
static void ngx_http_free_request(ngx_http_request_t *r, ngx_int_t error);
static void ngx_http_log_request(ngx_http_request_t *r);
static void ngx_http_close_connection(ngx_connection_t *c);

static u_char *ngx_http_log_error(ngx_log_t *log, u_char *buf, size_t len);
static u_char *ngx_http_log_error_handler(ngx_http_request_t *r,
                                          ngx_http_request_t *sr, u_char *buf, size_t len);

#if (NGX_HTTP_SSL)
static void ngx_http_ssl_handshake(ngx_event_t *rev);
static void ngx_http_ssl_handshake_handler(ngx_connection_t *c);
#endif


static char *ngx_http_client_errors[] = {

  /* NGX_HTTP_PARSE_INVALID_METHOD */
  "client sent invalid method",

  /* NGX_HTTP_PARSE_INVALID_REQUEST */
  "client sent invalid request",

  /* NGX_HTTP_PARSE_INVALID_09_METHOD */
  "client sent invalid method in HTTP/0.9 request"
};


ngx_http_header_t  ngx_http_headers_in[] = {
  { ngx_string("Host"), offsetof(ngx_http_headers_in_t, host),
    ngx_http_process_host },

  { ngx_string("Connection"), offsetof(ngx_http_headers_in_t, connection),
    ngx_http_process_connection },

  { ngx_string("If-Modified-Since"),
    offsetof(ngx_http_headers_in_t, if_modified_since),
    ngx_http_process_unique_header_line },

  { ngx_string("If-Unmodified-Since"),
    offsetof(ngx_http_headers_in_t, if_unmodified_since),
    ngx_http_process_unique_header_line },

  { ngx_string("User-Agent"), offsetof(ngx_http_headers_in_t, user_agent),
    ngx_http_process_user_agent },

  { ngx_string("Referer"), offsetof(ngx_http_headers_in_t, referer),
    ngx_http_process_header_line },

  { ngx_string("Content-Length"),
    offsetof(ngx_http_headers_in_t, content_length),
    ngx_http_process_unique_header_line },

  { ngx_string("Content-Type"),
    offsetof(ngx_http_headers_in_t, content_type),
    ngx_http_process_header_line },

  { ngx_string("Range"), offsetof(ngx_http_headers_in_t, range),
    ngx_http_process_header_line },

  { ngx_string("If-Range"),
    offsetof(ngx_http_headers_in_t, if_range),
    ngx_http_process_unique_header_line },

  { ngx_string("Transfer-Encoding"),
    offsetof(ngx_http_headers_in_t, transfer_encoding),
    ngx_http_process_header_line },

  { ngx_string("Expect"),
    offsetof(ngx_http_headers_in_t, expect),
    ngx_http_process_unique_header_line },

#if (NGX_HTTP_GZIP)
  { ngx_string("Accept-Encoding"),
    offsetof(ngx_http_headers_in_t, accept_encoding),
    ngx_http_process_header_line },

  { ngx_string("Via"), offsetof(ngx_http_headers_in_t, via),
    ngx_http_process_header_line },
#endif

  { ngx_string("Authorization"),
    offsetof(ngx_http_headers_in_t, authorization),
    ngx_http_process_unique_header_line },

  { ngx_string("Keep-Alive"), offsetof(ngx_http_headers_in_t, keep_alive),
    ngx_http_process_header_line },

#if (NGX_HTTP_PROXY || NGX_HTTP_REALIP || NGX_HTTP_GEO)
  { ngx_string("X-Forwarded-For"),
    offsetof(ngx_http_headers_in_t, x_forwarded_for),
    ngx_http_process_header_line },
#endif

#if (NGX_HTTP_REALIP)
  { ngx_string("X-Real-IP"),
    offsetof(ngx_http_headers_in_t, x_real_ip),
    ngx_http_process_header_line },
#endif

#if (NGX_HTTP_HEADERS)
  { ngx_string("Accept"), offsetof(ngx_http_headers_in_t, accept),
    ngx_http_process_header_line },

  { ngx_string("Accept-Language"),
    offsetof(ngx_http_headers_in_t, accept_language),
    ngx_http_process_header_line },
#endif

#if (NGX_HTTP_DAV)
  { ngx_string("Depth"), offsetof(ngx_http_headers_in_t, depth),
    ngx_http_process_header_line },

  { ngx_string("Destination"), offsetof(ngx_http_headers_in_t, destination),
    ngx_http_process_header_line },

  { ngx_string("Overwrite"), offsetof(ngx_http_headers_in_t, overwrite),
    ngx_http_process_header_line },

  { ngx_string("Date"), offsetof(ngx_http_headers_in_t, date),
    ngx_http_process_header_line },
#endif

  { ngx_string("Cookie"), 0, ngx_http_process_cookie },

  { ngx_null_string, 0, NULL }
};


void
ngx_http_init_connection(ngx_connection_t *c)
{
  ngx_event_t         *rev;
  ngx_http_log_ctx_t  *ctx;

  ctx = ngx_palloc(c->pool, sizeof(ngx_http_log_ctx_t));
  if (ctx == NULL) {
    ngx_http_close_connection(c);
    return;
  }

  ctx->connection = c;
  ctx->request = NULL;
  ctx->current_request = NULL;

  c->log->connection = c->number;
  c->log->handler = ngx_http_log_error;
  c->log->data = ctx;
  c->log->action = "reading client request line";

  c->log_error = NGX_ERROR_INFO;

  rev = c->read;
  rev->handler = ngx_http_init_request;
  c->write->handler = ngx_http_empty_handler;

#if (NGX_STAT_STUB)
  (void) ngx_atomic_fetch_add(ngx_stat_reading, 1);
#endif

  if (rev->ready) {
    /* the deferred accept(), rtsig, aio, iocp */

    if (ngx_use_accept_mutex) {
      ngx_post_event(rev, &ngx_posted_events);
      return;
    }

    ngx_http_init_request(rev);
    return;
  }

  ngx_add_timer(rev, c->listening->post_accept_timeout);

  if (ngx_handle_read_event(rev, 0) != NGX_OK) {
#if (NGX_STAT_STUB)
    (void) ngx_atomic_fetch_add(ngx_stat_reading, -1);
#endif
    ngx_http_close_connection(c);
    return;
  }
}


static void
ngx_http_init_request(ngx_event_t *rev)
{
  ngx_time_t                 *tp;
  ngx_uint_t                  i;
  ngx_connection_t           *c;
  ngx_http_request_t         *r;
  struct sockaddr_in         *sin;
  ngx_http_port_t            *port;
  ngx_http_in_addr_t         *addr;
  ngx_http_log_ctx_t         *ctx;
  ngx_http_addr_conf_t       *addr_conf;
  ngx_http_connection_t      *hc;
  ngx_http_core_srv_conf_t   *cscf;
  ngx_http_core_loc_conf_t   *clcf;
  ngx_http_core_main_conf_t  *cmcf;
#if (NGX_HAVE_INET6)
  struct sockaddr_in6        *sin6;
  ngx_http_in6_addr_t        *addr6;
#endif

#if (NGX_STAT_STUB)
  (void) ngx_atomic_fetch_add(ngx_stat_reading, -1);
#endif

  c = rev->data;

  if (rev->timedout) {
    ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");

    ngx_http_close_connection(c);
    return;
  }

  c->requests++;

  hc = c->data;

  if (hc == NULL) {
    hc = ngx_pcalloc(c->pool, sizeof(ngx_http_connection_t));
    if (hc == NULL) {
      ngx_http_close_connection(c);
      return;
    }
  }

  r = hc->request;

  if (r) {
    ngx_memzero(r, sizeof(ngx_http_request_t));

    r->pipeline = hc->pipeline;

    if (hc->nbusy) {
      r->header_in = hc->busy[0];
    }

  } else {
    r = ngx_pcalloc(c->pool, sizeof(ngx_http_request_t));
    if (r == NULL) {
      ngx_http_close_connection(c);
      return;
    }

    hc->request = r;
  }

  c->data = r;
  r->http_connection = hc;

  c->sent = 0;
  r->signature = NGX_HTTP_MODULE;

  /* find the server configuration for the address:port */

  port = c->listening->servers;

  r->connection = c;

  if (port->naddrs > 1) {

    /*
     * there are several addresses on this port and one of them
     * is an "*:port" wildcard so getsockname() in ngx_http_server_addr()
     * is required to determine a server address
     */

    if (ngx_connection_local_sockaddr(c, NULL, 0) != NGX_OK) {
      ngx_http_close_connection(c);
      return;
    }

    switch (c->local_sockaddr->sa_family) {

#if (NGX_HAVE_INET6)
      case AF_INET6:
        sin6 = (struct sockaddr_in6 *) c->local_sockaddr;

        addr6 = port->addrs;

        /* the last address is "*" */

        for (i = 0; i < port->naddrs - 1; i++) {
          if (ngx_memcmp(&addr6[i].addr6, &sin6->sin6_addr, 16) == 0) {
            break;
          }
        }

        addr_conf = &addr6[i].conf;

        break;
#endif

      default: /* AF_INET */
        sin = (struct sockaddr_in *) c->local_sockaddr;

        addr = port->addrs;

        /* the last address is "*" */

        for (i = 0; i < port->naddrs - 1; i++) {
          if (addr[i].addr == sin->sin_addr.s_addr) {
            break;
          }
        }

        addr_conf = &addr[i].conf;

        break;
    }

  } else {

    switch (c->local_sockaddr->sa_family) {

#if (NGX_HAVE_INET6)
      case AF_INET6:
        addr6 = port->addrs;
        addr_conf = &addr6[0].conf;
        break;
#endif

      default: /* AF_INET */
        addr = port->addrs;
        addr_conf = &addr[0].conf;
        break;
    }
  }

  r->virtual_names = addr_conf->virtual_names;

  /* the default server configuration for the address:port */
  cscf = addr_conf->default_server;

  r->main_conf = cscf->ctx->main_conf;
  r->srv_conf = cscf->ctx->srv_conf;
  r->loc_conf = cscf->ctx->loc_conf;

  rev->handler = ngx_http_process_request_line;
  r->read_event_handler = ngx_http_block_reading;

#if (NGX_HTTP_SSL)

  {
    ngx_http_ssl_srv_conf_t  *sscf;

    sscf = ngx_http_get_module_srv_conf(r, ngx_http_ssl_module);
    if (sscf->enable || addr_conf->ssl) {

      if (c->ssl == NULL) {

        c->log->action = "SSL handshaking";

        if (addr_conf->ssl && sscf->ssl.ctx == NULL) {
          ngx_log_error(NGX_LOG_ERR, c->log, 0,
                        "no \"ssl_certificate\" is defined "
                        "in server listening on SSL port");
          ngx_http_close_connection(c);
          return;
        }

        if (ngx_ssl_create_connection(&sscf->ssl, c, NGX_SSL_BUFFER)
            != NGX_OK)
        {
          ngx_http_close_connection(c);
          return;
        }

        rev->handler = ngx_http_ssl_handshake;
      }

      r->main_filter_need_in_memory = 1;
    }
  }

#endif

  clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
  c->log->file = clcf->error_log->file;
  if (!(c->log->log_level & NGX_LOG_DEBUG_CONNECTION)) {
    c->log->log_level = clcf->error_log->log_level;
  }

  if (c->buffer == NULL) {
    c->buffer = ngx_create_temp_buf(c->pool,
                                    cscf->client_header_buffer_size);
    if (c->buffer == NULL) {
      ngx_http_close_connection(c);
      return;
    }
  }

  if (r->header_in == NULL) {
    r->header_in = c->buffer;
  }

  r->pool = ngx_create_pool(cscf->request_pool_size, c->log);
  if (r->pool == NULL) {
    ngx_http_close_connection(c);
    return;
  }


  if (ngx_list_init(&r->headers_out.headers, r->pool, 20,
                    sizeof(ngx_table_elt_t))
      != NGX_OK)
  {
    ngx_destroy_pool(r->pool);
    ngx_http_close_connection(c);
    return;
  }

  r->ctx = ngx_pcalloc(r->pool, sizeof(void *) * ngx_http_max_module);
  if (r->ctx == NULL) {
    ngx_destroy_pool(r->pool);
    ngx_http_close_connection(c);
    return;
  }

  cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);

  r->variables = ngx_pcalloc(r->pool, cmcf->variables.nelts
                             * sizeof(ngx_http_variable_value_t));
  if (r->variables == NULL) {
    ngx_destroy_pool(r->pool);
    ngx_http_close_connection(c);
    return;
  }

  c->single_connection = 1;
  c->destroyed = 0;

  r->main = r;
  r->count = 1;

  tp = ngx_timeofday();
  r->start_sec = tp->sec;
  r->start_msec = tp->msec;

  r->method = NGX_HTTP_UNKNOWN;

  r->headers_in.content_length_n = -1;
  r->headers_in.keep_alive_n = -1;
  r->headers_out.content_length_n = -1;
  r->headers_out.last_modified_time = -1;

  r->uri_changes = NGX_HTTP_MAX_URI_CHANGES + 1;
  r->subrequests = NGX_HTTP_MAX_SUBREQUESTS + 1;

  r->http_state = NGX_HTTP_READING_REQUEST_STATE;

  ctx = c->log->data;
  ctx->request = r;
  ctx->current_request = r;
  r->log_handler = ngx_http_log_error_handler;

#if (NGX_STAT_STUB)
  (void) ngx_atomic_fetch_add(ngx_stat_reading, 1);
  r->stat_reading = 1;
  (void) ngx_atomic_fetch_add(ngx_stat_requests, 1);
#endif

  rev->handler(rev);
}


#if (NGX_HTTP_SSL)

static void
ngx_http_ssl_handshake(ngx_event_t *rev)
{
  u_char               buf[1];
  ssize_t              n;
  ngx_int_t            rc;
  ngx_connection_t    *c;
  ngx_http_request_t  *r;

  c = rev->data;
  r = c->data;

  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0,
                 "http check ssl handshake");

  if (rev->timedout) {
    ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
    c->timedout = 1;
    ngx_http_close_request(r, NGX_HTTP_REQUEST_TIME_OUT);
    return;
  }

  n = recv(c->fd, (char *) buf, 1, MSG_PEEK);

  if (n == -1 && ngx_socket_errno == NGX_EAGAIN) {

    if (!rev->timer_set) {
      ngx_add_timer(rev, c->listening->post_accept_timeout);
    }

    if (ngx_handle_read_event(rev, 0) != NGX_OK) {
      ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
    }

    return;
  }

  if (n == 1) {
    if (buf[0] & 0x80 /* SSLv2 */ || buf[0] == 0x16 /* SSLv3/TLSv1 */) {
      ngx_log_debug1(NGX_LOG_DEBUG_HTTP, rev->log, 0,
                     "https ssl handshake: 0x%02Xd", buf[0]);

      rc = ngx_ssl_handshake(c);

      if (rc == NGX_AGAIN) {

        if (!rev->timer_set) {
          ngx_add_timer(rev, c->listening->post_accept_timeout);
        }

        c->ssl->handler = ngx_http_ssl_handshake_handler;
        return;
      }

      ngx_http_ssl_handshake_handler(c);

      return;

    } else {
      ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0,
                     "plain http");

      r->plain_http = 1;
    }
  }

  c->log->action = "reading client request line";

  rev->handler = ngx_http_process_request_line;
  ngx_http_process_request_line(rev);
}


static void
ngx_http_ssl_handshake_handler(ngx_connection_t *c)
{
  ngx_http_request_t  *r;

  if (c->ssl->handshaked) {

    /*
     * The majority of browsers do not send the "close notify" alert.
     * Among them are MSIE, old Mozilla, Netscape 4, Konqueror,
     * and Links.  And what is more, MSIE ignores the server's alert.
     *
     * Opera and recent Mozilla send the alert.
     */

    c->ssl->no_wait_shutdown = 1;

    c->read->handler = ngx_http_process_request_line;
    /* STUB: epoll edge */ c->write->handler = ngx_http_empty_handler;

    ngx_http_process_request_line(c->read);

    return;
  }

  r = c->data;

  ngx_http_close_request(r, NGX_HTTP_BAD_REQUEST);

  return;
}

#ifdef SSL_CTRL_SET_TLSEXT_HOSTNAME

int
ngx_http_ssl_servername(ngx_ssl_conn_t *ssl_conn, int *ad, void *arg)
{
  size_t                    len;
  u_char                   *host;
  const char               *servername;
  ngx_connection_t         *c;
  ngx_http_request_t       *r;
  ngx_http_ssl_srv_conf_t  *sscf;

  servername = SSL_get_servername(ssl_conn, TLSEXT_NAMETYPE_host_name);

  if (servername == NULL) {
    return SSL_TLSEXT_ERR_NOACK;
  }

  c = ngx_ssl_get_connection(ssl_conn);

  ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                 "SSL server name: \"%s\"", servername);

  len = ngx_strlen(servername);

  if (len == 0) {
    return SSL_TLSEXT_ERR_NOACK;
  }

  r = c->data;

  host = (u_char *) servername;

  len = ngx_http_validate_host(r, &host, len, 1);

  if (len <= 0) {
    return SSL_TLSEXT_ERR_NOACK;
  }

  if (ngx_http_find_virtual_server(r, host, len) != NGX_OK) {
    return SSL_TLSEXT_ERR_NOACK;
  }

  sscf = ngx_http_get_module_srv_conf(r, ngx_http_ssl_module);

  if (sscf->ssl.ctx) {
    SSL_set_SSL_CTX(ssl_conn, sscf->ssl.ctx);

    /*
     * SSL_set_SSL_CTX() only changes certs as of 1.0.0d
     * adjust other things we care about
     */

    SSL_set_verify(ssl_conn, SSL_CTX_get_verify_mode(sscf->ssl.ctx),
                   SSL_CTX_get_verify_callback(sscf->ssl.ctx));

    SSL_set_verify_depth(ssl_conn, SSL_CTX_get_verify_depth(sscf->ssl.ctx));

#ifdef SSL_CTRL_CLEAR_OPTIONS
    /* only in 0.9.8m+ */
    SSL_clear_options(ssl_conn, SSL_get_options(ssl_conn) &
                      ~SSL_CTX_get_options(sscf->ssl.ctx));
#endif

    SSL_set_options(ssl_conn, SSL_CTX_get_options(sscf->ssl.ctx));
  }

  return SSL_TLSEXT_ERR_OK;
}

#endif

#endif


static void
ngx_http_process_request_line(ngx_event_t *rev)
{
  u_char                    *host;
  ssize_t                    n;
  ngx_int_t                  rc, rv;
  ngx_connection_t          *c;
  ngx_http_request_t        *r;
  ngx_http_core_srv_conf_t  *cscf;

  c = rev->data;
  r = c->data;

  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0,
                 "http process request line");

  if (rev->timedout) {
    ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
    c->timedout = 1;
    ngx_http_close_request(r, NGX_HTTP_REQUEST_TIME_OUT);
    return;
  }

  rc = NGX_AGAIN;

  for ( ;; ) {

    if (rc == NGX_AGAIN) {
      n = ngx_http_read_request_header(r);

      if (n == NGX_AGAIN || n == NGX_ERROR) {
        return;
      }
    }

    rc = ngx_http_parse_request_line(r, r->header_in);

    if (rc == NGX_OK) {

      /* the request line has been parsed successfully */

      r->request_line.len = r->request_end - r->request_start;
      r->request_line.data = r->request_start;


      if (r->args_start) {
        r->uri.len = r->args_start - 1 - r->uri_start;
      } else {
        r->uri.len = r->uri_end - r->uri_start;
      }


      if (r->complex_uri || r->quoted_uri) {

        r->uri.data = ngx_pnalloc(r->pool, r->uri.len + 1);
        if (r->uri.data == NULL) {
          ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
          return;
        }

        cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);

        rc = ngx_http_parse_complex_uri(r, cscf->merge_slashes);

        if (rc == NGX_HTTP_PARSE_INVALID_REQUEST) {
          ngx_log_error(NGX_LOG_INFO, c->log, 0,
                        "client sent invalid request");
          ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
          return;
        }

      } else {
        r->uri.data = r->uri_start;
      }


      r->unparsed_uri.len = r->uri_end - r->uri_start;
      r->unparsed_uri.data = r->uri_start;

      r->valid_unparsed_uri = r->space_in_uri ? 0 : 1;

      r->method_name.len = r->method_end - r->request_start + 1;
      r->method_name.data = r->request_line.data;


      if (r->http_protocol.data) {
        r->http_protocol.len = r->request_end - r->http_protocol.data;
      }


      if (r->uri_ext) {
        if (r->args_start) {
          r->exten.len = r->args_start - 1 - r->uri_ext;
        } else {
          r->exten.len = r->uri_end - r->uri_ext;
        }

        r->exten.data = r->uri_ext;
      }


      if (r->args_start && r->uri_end > r->args_start) {
        r->args.len = r->uri_end - r->args_start;
        r->args.data = r->args_start;
      }

#if (NGX_WIN32)
      {
        u_char  *p;

        p = r->uri.data + r->uri.len - 1;

        while (p > r->uri.data) {

          if (*p == ' ') {
            p--;
            continue;
          }

          if (*p == '.') {
            p--;
            continue;
          }

          if (ngx_strncasecmp(p - 6, (u_char *) "::$data", 7) == 0) {
            p -= 7;
            continue;
          }

          break;
        }

        if (p != r->uri.data + r->uri.len - 1) {
          r->uri.len = p + 1 - r->uri.data;
          ngx_http_set_exten(r);
        }

      }
#endif

      ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                     "http request line: \"%V\"", &r->request_line);

      ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                     "http uri: \"%V\"", &r->uri);

      ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                     "http args: \"%V\"", &r->args);

      ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                     "http exten: \"%V\"", &r->exten);

      if (r->host_start && r->host_end) {

        host = r->host_start;
        n = ngx_http_validate_host(r, &host,
                                   r->host_end - r->host_start, 0);

        if (n == 0) {
          ngx_log_error(NGX_LOG_INFO, c->log, 0,
                        "client sent invalid host in request line");
          ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
          return;
        }

        if (n < 0) {
          ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
          return;
        }

        r->headers_in.server.len = n;
        r->headers_in.server.data = host;
      }

      if (r->http_version < NGX_HTTP_VERSION_10) {

        if (ngx_http_find_virtual_server(r, r->headers_in.server.data,
                                         r->headers_in.server.len)
            == NGX_ERROR)
        {
          ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
          return;
        }

        ngx_http_process_request(r);
        return;
      }


      if (ngx_list_init(&r->headers_in.headers, r->pool, 20,
                        sizeof(ngx_table_elt_t))
          != NGX_OK)
      {
        ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        return;
      }


      if (ngx_array_init(&r->headers_in.cookies, r->pool, 2,
                         sizeof(ngx_table_elt_t *))
          != NGX_OK)
      {
        ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        return;
      }

      c->log->action = "reading client request headers";

      rev->handler = ngx_http_process_request_headers;
      ngx_http_process_request_headers(rev);

      return;
    }

    if (rc != NGX_AGAIN) {

      /* there was error while a request line parsing */

      ngx_log_error(NGX_LOG_INFO, c->log, 0,
                    ngx_http_client_errors[rc - NGX_HTTP_CLIENT_ERROR]);
      ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
      return;
    }

    /* NGX_AGAIN: a request line parsing is still incomplete */

    if (r->header_in->pos == r->header_in->end) {

      rv = ngx_http_alloc_large_header_buffer(r, 1);

      if (rv == NGX_ERROR) {
        ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        return;
      }

      if (rv == NGX_DECLINED) {
        r->request_line.len = r->header_in->end - r->request_start;
        r->request_line.data = r->request_start;

        ngx_log_error(NGX_LOG_INFO, c->log, 0,
                      "client sent too long URI");
        ngx_http_finalize_request(r, NGX_HTTP_REQUEST_URI_TOO_LARGE);
        return;
      }
    }
  }
}


static void
ngx_http_process_request_headers(ngx_event_t *rev)
{
  u_char                     *p;
  size_t                      len;
  ssize_t                     n;
  ngx_int_t                   rc, rv;
  ngx_table_elt_t            *h;
  ngx_connection_t           *c;
  ngx_http_header_t          *hh;
  ngx_http_request_t         *r;
  ngx_http_core_srv_conf_t   *cscf;
  ngx_http_core_main_conf_t  *cmcf;

  c = rev->data;
  r = c->data;

  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, rev->log, 0,
                 "http process request header line");

  if (rev->timedout) {
    ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT, "client timed out");
    c->timedout = 1;
    ngx_http_close_request(r, NGX_HTTP_REQUEST_TIME_OUT);
    return;
  }

  cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);
  cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);

  rc = NGX_AGAIN;

  for ( ;; ) {

    if (rc == NGX_AGAIN) {

      if (r->header_in->pos == r->header_in->end) {

        rv = ngx_http_alloc_large_header_buffer(r, 0);

        if (rv == NGX_ERROR) {
          ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
          return;
        }

        if (rv == NGX_DECLINED) {
          p = r->header_name_start;

          r->lingering_close = 1;

          if (p == NULL) {
            ngx_log_error(NGX_LOG_INFO, c->log, 0,
                          "client sent too large request");
            ngx_http_finalize_request(r,
                                      NGX_HTTP_REQUEST_HEADER_TOO_LARGE);
            return;
          }

          len = r->header_in->end - p;

          if (len > NGX_MAX_ERROR_STR - 300) {
            len = NGX_MAX_ERROR_STR - 300;
            p[len++] = '.'; p[len++] = '.'; p[len++] = '.';
          }

          ngx_log_error(NGX_LOG_INFO, c->log, 0,
                        "client sent too long header line: \"%*s\"",
                        len, r->header_name_start);

          ngx_http_finalize_request(r,
                                    NGX_HTTP_REQUEST_HEADER_TOO_LARGE);
          return;
        }
      }

      n = ngx_http_read_request_header(r);

      if (n == NGX_AGAIN || n == NGX_ERROR) {
        return;
      }
    }

    rc = ngx_http_parse_header_line(r, r->header_in,
                                    cscf->underscores_in_headers);

    if (rc == NGX_OK) {

      if (r->invalid_header && cscf->ignore_invalid_headers) {

        /* there was error while a header line parsing */

        ngx_log_error(NGX_LOG_INFO, c->log, 0,
                      "client sent invalid header line: \"%*s\"",
                      r->header_end - r->header_name_start,
                      r->header_name_start);
        continue;
      }

      /* a header line has been parsed successfully */

      h = ngx_list_push(&r->headers_in.headers);
      if (h == NULL) {
        ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        return;
      }

      h->hash = r->header_hash;

      h->key.len = r->header_name_end - r->header_name_start;
      h->key.data = r->header_name_start;
      h->key.data[h->key.len] = '\0';

      h->value.len = r->header_end - r->header_start;
      h->value.data = r->header_start;
      h->value.data[h->value.len] = '\0';

      h->lowcase_key = ngx_pnalloc(r->pool, h->key.len);
      if (h->lowcase_key == NULL) {
        ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
        return;
      }

      if (h->key.len == r->lowcase_index) {
        ngx_memcpy(h->lowcase_key, r->lowcase_header, h->key.len);

      } else {
        ngx_strlow(h->lowcase_key, h->key.data, h->key.len);
      }

      hh = ngx_hash_find(&cmcf->headers_in_hash, h->hash,
                         h->lowcase_key, h->key.len);

      if (hh && hh->handler(r, h, hh->offset) != NGX_OK) {
        return;
      }

      ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                     "http header: \"%V: %V\"",
                     &h->key, &h->value);

      continue;
    }

    if (rc == NGX_HTTP_PARSE_HEADER_DONE) {

      /* a whole header has been parsed successfully */

      ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                     "http header done");

      r->request_length += r->header_in->pos - r->header_in->start;

      r->http_state = NGX_HTTP_PROCESS_REQUEST_STATE;

      rc = ngx_http_process_request_header(r);

      if (rc != NGX_OK) {
        return;
      }

      ngx_http_process_request(r);

      return;
    }

    if (rc == NGX_AGAIN) {

      /* a header line parsing is still not complete */

      continue;
    }

    /* rc == NGX_HTTP_PARSE_INVALID_HEADER: "\r" is not followed by "\n" */

    ngx_log_error(NGX_LOG_INFO, c->log, 0,
                  "client sent invalid header line: \"%*s\\r...\"",
                  r->header_end - r->header_name_start,
                  r->header_name_start);
    ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
    return;
  }
}


static ssize_t
ngx_http_read_request_header(ngx_http_request_t *r)
{
  ssize_t                    n;
  ngx_event_t               *rev;
  ngx_connection_t          *c;
  ngx_http_core_srv_conf_t  *cscf;

  c = r->connection;
  rev = c->read;

  n = r->header_in->last - r->header_in->pos;

  if (n > 0) {
    return n;
  }

  if (rev->ready) {
    n = c->recv(c, r->header_in->last,
                r->header_in->end - r->header_in->last);
  } else {
    n = NGX_AGAIN;
  }

  if (n == NGX_AGAIN) {
    if (!rev->timer_set) {
      cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);
      ngx_add_timer(rev, cscf->client_header_timeout);
    }

    if (ngx_handle_read_event(rev, 0) != NGX_OK) {
      ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
      return NGX_ERROR;
    }

    return NGX_AGAIN;
  }

  if (n == 0) {
    ngx_log_error(NGX_LOG_INFO, c->log, 0,
                  "client closed prematurely connection");
  }

  if (n == 0 || n == NGX_ERROR) {
    c->error = 1;
    c->log->action = "reading client request headers";

    ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
    return NGX_ERROR;
  }

  r->header_in->last += n;

  return n;
}


static ngx_int_t
ngx_http_alloc_large_header_buffer(ngx_http_request_t *r,
                                   ngx_uint_t request_line)
{
  u_char                    *old, *new;
  ngx_buf_t                 *b;
  ngx_http_connection_t     *hc;
  ngx_http_core_srv_conf_t  *cscf;

  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                 "http alloc large header buffer");

  if (request_line && r->state == 0) {

    /* the client fills up the buffer with "\r\n" */

    r->request_length += r->header_in->end - r->header_in->start;

    r->header_in->pos = r->header_in->start;
    r->header_in->last = r->header_in->start;

    return NGX_OK;
  }

  old = request_line ? r->request_start : r->header_name_start;

  cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);

  if (r->state != 0
      && (size_t) (r->header_in->pos - old)
      >= cscf->large_client_header_buffers.size)
  {
    return NGX_DECLINED;
  }

  hc = r->http_connection;

  if (hc->nfree) {
    b = hc->free[--hc->nfree];

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http large header free: %p %uz",
                   b->pos, b->end - b->last);

  } else if (hc->nbusy < cscf->large_client_header_buffers.num) {

    if (hc->busy == NULL) {
      hc->busy = ngx_palloc(r->connection->pool,
                            cscf->large_client_header_buffers.num * sizeof(ngx_buf_t *));
      if (hc->busy == NULL) {
        return NGX_ERROR;
      }
    }

    b = ngx_create_temp_buf(r->connection->pool,
                            cscf->large_client_header_buffers.size);
    if (b == NULL) {
      return NGX_ERROR;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                   "http large header alloc: %p %uz",
                   b->pos, b->end - b->last);

  } else {
    return NGX_DECLINED;
  }

  hc->busy[hc->nbusy++] = b;

  if (r->state == 0) {
    /*
     * r->state == 0 means that a header line was parsed successfully
     * and we do not need to copy incomplete header line and
     * to relocate the parser header pointers
     */

    r->request_length += r->header_in->end - r->header_in->start;

    r->header_in = b;

    return NGX_OK;
  }

  ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                 "http large header copy: %d", r->header_in->pos - old);

  r->request_length += old - r->header_in->start;

  new = b->start;

  ngx_memcpy(new, old, r->header_in->pos - old);

  b->pos = new + (r->header_in->pos - old);
  b->last = new + (r->header_in->pos - old);

  if (request_line) {
    r->request_start = new;

    if (r->request_end) {
      r->request_end = new + (r->request_end - old);
    }

    r->method_end = new + (r->method_end - old);

    r->uri_start = new + (r->uri_start - old);
    r->uri_end = new + (r->uri_end - old);

    if (r->schema_start) {
      r->schema_start = new + (r->schema_start - old);
      r->schema_end = new + (r->schema_end - old);
    }

    if (r->host_start) {
      r->host_start = new + (r->host_start - old);
      if (r->host_end) {
        r->host_end = new + (r->host_end - old);
      }
    }

    if (r->port_start) {
      r->port_start = new + (r->port_start - old);
      r->port_end = new + (r->port_end - old);
    }

    if (r->uri_ext) {
      r->uri_ext = new + (r->uri_ext - old);
    }

    if (r->args_start) {
      r->args_start = new + (r->args_start - old);
    }

    if (r->http_protocol.data) {
      r->http_protocol.data = new + (r->http_protocol.data - old);
    }

  } else {
    r->header_name_start = new;
    r->header_name_end = new + (r->header_name_end - old);
    r->header_start = new + (r->header_start - old);
    r->header_end = new + (r->header_end - old);
  }

  r->header_in = b;

  return NGX_OK;
}


static ngx_int_t
ngx_http_process_header_line(ngx_http_request_t *r, ngx_table_elt_t *h,
                             ngx_uint_t offset)
{
  ngx_table_elt_t  **ph;

  ph = (ngx_table_elt_t **) ((char *) &r->headers_in + offset);

  if (*ph == NULL) {
    *ph = h;
  }

  return NGX_OK;
}


static ngx_int_t
ngx_http_process_unique_header_line(ngx_http_request_t *r, ngx_table_elt_t *h,
                                    ngx_uint_t offset)
{
  ngx_table_elt_t  **ph;

  ph = (ngx_table_elt_t **) ((char *) &r->headers_in + offset);

  if (*ph == NULL) {
    *ph = h;
    return NGX_OK;
  }

  ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                "client sent duplicate header line: \"%V: %V\", "
                "previous value: \"%V: %V\"",
                &h->key, &h->value, &(*ph)->key, &(*ph)->value);

  ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);

  return NGX_ERROR;
}


static ngx_int_t
ngx_http_process_host(ngx_http_request_t *r, ngx_table_elt_t *h,
                      ngx_uint_t offset)
{
  u_char   *host;
  ssize_t   len;

  if (r->headers_in.host == NULL) {
    r->headers_in.host = h;
  }

  host = h->value.data;
  len = ngx_http_validate_host(r, &host, h->value.len, 0);

  if (len == 0) {
    ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                  "client sent invalid host header");
    ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
    return NGX_ERROR;
  }

  if (len < 0) {
    ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
    return NGX_ERROR;
  }

  if (r->headers_in.server.len) {
    return NGX_OK;
  }

  r->headers_in.server.len = len;
  r->headers_in.server.data = host;

  return NGX_OK;
}


static ngx_int_t
ngx_http_process_connection(ngx_http_request_t *r, ngx_table_elt_t *h,
                            ngx_uint_t offset)
{
  if (ngx_strcasestrn(h->value.data, "close", 5 - 1)) {
    r->headers_in.connection_type = NGX_HTTP_CONNECTION_CLOSE;

  } else if (ngx_strcasestrn(h->value.data, "keep-alive", 10 - 1)) {
    r->headers_in.connection_type = NGX_HTTP_CONNECTION_KEEP_ALIVE;
  }

  return NGX_OK;
}


static ngx_int_t
ngx_http_process_user_agent(ngx_http_request_t *r, ngx_table_elt_t *h,
                            ngx_uint_t offset)
{
  u_char  *user_agent, *msie;

  if (r->headers_in.user_agent) {
    return NGX_OK;
  }

  r->headers_in.user_agent = h;

  /* check some widespread browsers while the header is in CPU cache */

  user_agent = h->value.data;

  msie = ngx_strstrn(user_agent, "MSIE ", 5 - 1);

  if (msie && msie + 7 < user_agent + h->value.len) {

    r->headers_in.msie = 1;

    if (msie[6] == '.') {

      switch (msie[5]) {
        case '4':
        case '5':
            r->headers_in.msie6 = 1;
        break;
        case '6':
          if (ngx_strstrn(msie + 8, "SV1", 3 - 1) == NULL) {
            r->headers_in.msie6 = 1;
          }
          break;
      }
    }

#if 0
    /* MSIE ignores the SSL "close notify" alert */
    if (c->ssl) {
      c->ssl->no_send_shutdown = 1;
    }
#endif
  }

  if (ngx_strstrn(user_agent, "Opera", 5 - 1)) {
    r->headers_in.opera = 1;
    r->headers_in.msie = 0;
    r->headers_in.msie6 = 0;
  }

  if (!r->headers_in.msie && !r->headers_in.opera) {

    if (ngx_strstrn(user_agent, "Gecko/", 6 - 1)) {
      r->headers_in.gecko = 1;

    } else if (ngx_strstrn(user_agent, "Chrome/", 7 - 1)) {
      r->headers_in.chrome = 1;

    } else if (ngx_strstrn(user_agent, "Safari/", 7 - 1)) {
      r->headers_in.safari = 1;

    } else if (ngx_strstrn(user_agent, "Konqueror", 9 - 1)) {
      r->headers_in.konqueror = 1;
    }
  }

  return NGX_OK;
}


static ngx_int_t
ngx_http_process_cookie(ngx_http_request_t *r, ngx_table_elt_t *h,
                        ngx_uint_t offset)
{
  ngx_table_elt_t  **cookie;

  cookie = ngx_array_push(&r->headers_in.cookies);
  if (cookie) {
    *cookie = h;
    return NGX_OK;
  }

  ngx_http_close_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);

  return NGX_ERROR;
}


static ngx_int_t
ngx_http_process_request_header(ngx_http_request_t *r)
{
  if (ngx_http_find_virtual_server(r, r->headers_in.server.data,
                                   r->headers_in.server.len)
      == NGX_ERROR)
  {
    ngx_http_finalize_request(r, NGX_HTTP_INTERNAL_SERVER_ERROR);
    return NGX_ERROR;
  }

  if (r->headers_in.host == NULL && r->http_version > NGX_HTTP_VERSION_10) {
    ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                  "client sent HTTP/1.1 request without \"Host\" header");
    ngx_http_finalize_request(r, NGX_HTTP_BAD_REQUEST);
    return NGX_ERROR;
  }

  if (r->headers_in.content_length) {
    r->headers_in.content_length_n =
        ngx_atoof(r->headers_in.content_length->value.data,
                  r->headers_in.content_length->value.len);

    if (r->headers_in.content_length_n == NGX_ERROR) {
      ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                    "client sent invalid \"Content-Length\" header");
      ngx_http_finalize_request(r, NGX_HTTP_LENGTH_REQUIRED);
      return NGX_ERROR;
    }
  }

  if (r->method & NGX_HTTP_PUT && r->headers_in.content_length_n == -1) {
    ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                  "client sent %V method without \"Content-Length\" header",
                  &r->method_name);
    ngx_http_finalize_request(r, NGX_HTTP_LENGTH_REQUIRED);
    return NGX_ERROR;
  }

  if (r->method & NGX_HTTP_TRACE) {
    ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                  "client sent TRACE method");
    ngx_http_finalize_request(r, NGX_HTTP_NOT_ALLOWED);
    return NGX_ERROR;
  }

  if (r->headers_in.transfer_encoding
      && ngx_strcasestrn(r->headers_in.transfer_encoding->value.data,
                         "chunked", 7 - 1))
  {
    ngx_log_error(NGX_LOG_INFO, r->connection->log, 0,
                  "client sent \"Transfer-Encoding: chunked\" header");
    ngx_http_finalize_request(r, NGX_HTTP_LENGTH_REQUIRED);
    return NGX_ERROR;
  }

  if (r->headers_in.connection_type == NGX_HTTP_CONNECTION_KEEP_ALIVE) {
    if (r->headers_in.keep_alive) {
      r->headers_in.keep_alive_n =
          ngx_atotm(r->headers_in.keep_alive->value.data,
                    r->headers_in.keep_alive->value.len);
    }
  }

  return NGX_OK;
}


static void
ngx_http_process_request(ngx_http_request_t *r)
{
  ngx_connection_t  *c;

  c = r->connection;

  if (r->plain_http) {
    ngx_log_error(NGX_LOG_INFO, c->log, 0,
                  "client sent plain HTTP request to HTTPS port");
    ngx_http_finalize_request(r, NGX_HTTP_TO_HTTPS);
    return;
  }

#if (NGX_HTTP_SSL)

  if (c->ssl) {
    long                      rc;
    X509                     *cert;
    ngx_http_ssl_srv_conf_t  *sscf;

    sscf = ngx_http_get_module_srv_conf(r, ngx_http_ssl_module);

    if (sscf->verify) {
      rc = SSL_get_verify_result(c->ssl->connection);

      if (rc != X509_V_OK) {
        ngx_log_error(NGX_LOG_INFO, c->log, 0,
                      "client SSL certificate verify error: (%l:%s)",
                      rc, X509_verify_cert_error_string(rc));

        ngx_ssl_remove_cached_session(sscf->ssl.ctx,
                                      (SSL_get0_session(c->ssl->connection)));

        ngx_http_finalize_request(r, NGX_HTTPS_CERT_ERROR);
        return;
      }

      if (sscf->verify == 1) {
        cert = SSL_get_peer_certificate(c->ssl->connection);

        if (cert == NULL) {
          ngx_log_error(NGX_LOG_INFO, c->log, 0,
                        "client sent no required SSL certificate");

          ngx_ssl_remove_cached_session(sscf->ssl.ctx,
                                        (SSL_get0_session(c->ssl->connection)));

          ngx_http_finalize_request(r, NGX_HTTPS_NO_CERT);
          return;
        }

        X509_free(cert);
      }
    }
  }

#endif

  if (c->read->timer_set) {
    ngx_del_timer(c->read);
  }

#if (NGX_STAT_STUB)
  (void) ngx_atomic_fetch_add(ngx_stat_reading, -1);
  r->stat_reading = 0;
  (void) ngx_atomic_fetch_add(ngx_stat_writing, 1);
  r->stat_writing = 1;
#endif

  c->read->handler = ngx_http_request_handler;
  c->write->handler = ngx_http_request_handler;
  r->read_event_handler = ngx_http_block_reading;

  ngx_http_handler(r);

  ngx_http_run_posted_requests(c);
}


static ssize_t
ngx_http_validate_host(ngx_http_request_t *r, u_char **host, size_t len,
                       ngx_uint_t alloc)
{
  u_char  *h, ch;
  size_t   i, dot_pos, host_len;

  enum {
    sw_usual = 0,
    sw_literal,
    sw_rest
  } state;

  dot_pos = len;
  host_len = len;

  h = *host;

  state = sw_usual;

  for (i = 0; i < len; i++) {
    ch = h[i];

    switch (ch) {

      case '.':
        if (dot_pos == i - 1) {
          return 0;
        }
        dot_pos = i;
        break;

      case ':':
        if (state == sw_usual) {
          host_len = i;
          state = sw_rest;
        }
        break;

      case '[':
        if (i == 0) {
          state = sw_literal;
        }
        break;

      case ']':
        if (state == sw_literal) {
          host_len = i + 1;
          state = sw_rest;
        }
        break;

      case '\0':
        return 0;

      default:

        if (ngx_path_separator(ch)) {
          return 0;
        }

        if (ch >= 'A' && ch <= 'Z') {
          alloc = 1;
        }

        break;
    }
  }

  if (dot_pos == host_len - 1) {
    host_len--;
  }

  if (alloc) {
    *host = ngx_pnalloc(r->pool, host_len);
    if (*host == NULL) {
      return -1;
    }

    ngx_strlow(*host, h, host_len);
  }

  return host_len;
}


static ngx_int_t
ngx_http_find_virtual_server(ngx_http_request_t *r, u_char *host, size_t len)
{
  ngx_http_core_loc_conf_t  *clcf;
  ngx_http_core_srv_conf_t  *cscf;

  if (r->virtual_names == NULL) {
    return NGX_DECLINED;
  }

  cscf = ngx_hash_find_combined(&r->virtual_names->names,
                                ngx_hash_key(host, len), host, len);

  if (cscf) {
    goto found;
  }

#if (NGX_PCRE)

  if (len && r->virtual_names->nregex) {
    ngx_int_t                n;
    ngx_uint_t               i;
    ngx_str_t                name;
    ngx_http_server_name_t  *sn;

    name.len = len;
    name.data = host;

    sn = r->virtual_names->regex;

    for (i = 0; i < r->virtual_names->nregex; i++) {

      n = ngx_http_regex_exec(r, sn[i].regex, &name);

      if (n == NGX_OK) {
        cscf = sn[i].server;
        goto found;
      }

      if (n == NGX_DECLINED) {
        continue;
      }

      return NGX_ERROR;
    }
  }

#endif

  return NGX_OK;

found:

  r->srv_conf = cscf->ctx->srv_conf;
  r->loc_conf = cscf->ctx->loc_conf;

  clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
  r->connection->log->file = clcf->error_log->file;

  if (!(r->connection->log->log_level & NGX_LOG_DEBUG_CONNECTION)) {
    r->connection->log->log_level = clcf->error_log->log_level;
  }

  return NGX_OK;
}


static void
ngx_http_request_handler(ngx_event_t *ev)
{
  ngx_connection_t    *c;
  ngx_http_request_t  *r;
  ngx_http_log_ctx_t  *ctx;

  c = ev->data;
  r = c->data;

  ctx = c->log->data;
  ctx->current_request = r;

  ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                 "http run request: \"%V?%V\"", &r->uri, &r->args);

  if (ev->write) {
    r->write_event_handler(r);

  } else {
    r->read_event_handler(r);
  }

  ngx_http_run_posted_requests(c);
}


void
ngx_http_run_posted_requests(ngx_connection_t *c)
{
  ngx_http_request_t         *r;
  ngx_http_log_ctx_t         *ctx;
  ngx_http_posted_request_t  *pr;

  for ( ;; ) {

    if (c->destroyed) {
      return;
    }

    r = c->data;
    pr = r->main->posted_requests;

    if (pr == NULL) {
      return;
    }

    r->main->posted_requests = pr->next;

    r = pr->request;

    ctx = c->log->data;
    ctx->current_request = r;

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                   "http posted request: \"%V?%V\"", &r->uri, &r->args);

    r->write_event_handler(r);
  }
}


ngx_int_t
ngx_http_post_request(ngx_http_request_t *r, ngx_http_posted_request_t *pr)
{
  ngx_http_posted_request_t  **p;

  if (pr == NULL) {
    pr = ngx_palloc(r->pool, sizeof(ngx_http_posted_request_t));
    if (pr == NULL) {
      return NGX_ERROR;
    }
  }

  pr->request = r;
  pr->next = NULL;

  for (p = &r->main->posted_requests; *p; p = &(*p)->next) { /* void */ }

  *p = pr;

  return NGX_OK;
}


void
ngx_http_finalize_request(ngx_http_request_t *r, ngx_int_t rc)
{
  ngx_connection_t          *c;
  ngx_http_request_t        *pr;
  ngx_http_core_loc_conf_t  *clcf;

  c = r->connection;

  ngx_log_debug5(NGX_LOG_DEBUG_HTTP, c->log, 0,
                 "http finalize request: %d, \"%V?%V\" a:%d, c:%d",
                 rc, &r->uri, &r->args, r == c->data, r->main->count);

  if (rc == NGX_DONE) {
    ngx_http_finalize_connection(r);
    return;
  }

  if (rc == NGX_OK && r->filter_finalize) {
    c->error = 1;
    return;
  }

  if (rc == NGX_DECLINED) {
    r->content_handler = NULL;
    r->write_event_handler = ngx_http_core_run_phases;
    ngx_http_core_run_phases(r);
    return;
  }

  if (r != r->main && r->post_subrequest) {
    rc = r->post_subrequest->handler(r, r->post_subrequest->data, rc);
  }

  if (rc == NGX_ERROR
      || rc == NGX_HTTP_REQUEST_TIME_OUT
      || rc == NGX_HTTP_CLIENT_CLOSED_REQUEST
      || c->error)
  {
    if (ngx_http_post_action(r) == NGX_OK) {
      return;
    }

    if (r->main->blocked) {
      r->write_event_handler = ngx_http_request_finalizer;
    }

    ngx_http_terminate_request(r, rc);
    return;
  }

  if (rc >= NGX_HTTP_SPECIAL_RESPONSE
      || rc == NGX_HTTP_CREATED
      || rc == NGX_HTTP_NO_CONTENT)
  {
    if (rc == NGX_HTTP_CLOSE) {
      ngx_http_terminate_request(r, rc);
      return;
    }

    if (r == r->main) {
      if (c->read->timer_set) {
        ngx_del_timer(c->read);
      }

      if (c->write->timer_set) {
        ngx_del_timer(c->write);
      }
    }

    c->read->handler = ngx_http_request_handler;
    c->write->handler = ngx_http_request_handler;

    ngx_http_finalize_request(r, ngx_http_special_response_handler(r, rc));
    return;
  }

  if (r != r->main) {

    if (r->buffered || r->postponed) {

      if (ngx_http_set_write_handler(r) != NGX_OK) {
        ngx_http_terminate_request(r, 0);
      }

      return;
    }

#if (NGX_DEBUG)
    if (r != c->data) {
      ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                     "http finalize non-active request: \"%V?%V\"",
                     &r->uri, &r->args);
    }
#endif

    pr = r->parent;

    if (r == c->data) {

      r->main->count--;
      r->main->subrequests++;

      if (!r->logged) {

        clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

        if (clcf->log_subrequest) {
          ngx_http_log_request(r);
        }

        r->logged = 1;

      } else {
        ngx_log_error(NGX_LOG_ALERT, c->log, 0,
                      "subrequest: \"%V?%V\" logged again",
                      &r->uri, &r->args);
      }

      r->done = 1;

      if (pr->postponed && pr->postponed->request == r) {
        pr->postponed = pr->postponed->next;
      }

      c->data = pr;

    } else {

      r->write_event_handler = ngx_http_request_finalizer;

      if (r->waited) {
        r->done = 1;
      }
    }

    if (ngx_http_post_request(pr, NULL) != NGX_OK) {
      r->main->count++;
      ngx_http_terminate_request(r, 0);
      return;
    }

    ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                   "http wake parent request: \"%V?%V\"",
                   &pr->uri, &pr->args);

    return;
  }

  if (r->buffered || c->buffered || r->postponed || r->blocked) {

    if (ngx_http_set_write_handler(r) != NGX_OK) {
      ngx_http_terminate_request(r, 0);
    }

    return;
  }

  if (r != c->data) {
    ngx_log_error(NGX_LOG_ALERT, c->log, 0,
                  "http finalize non-active request: \"%V?%V\"",
                  &r->uri, &r->args);
    return;
  }

  r->done = 1;
  r->write_event_handler = ngx_http_request_empty_handler;

  if (!r->post_action) {
    r->request_complete = 1;
  }

  if (ngx_http_post_action(r) == NGX_OK) {
    return;
  }

  if (c->read->timer_set) {
    ngx_del_timer(c->read);
  }

  if (c->write->timer_set) {
    c->write->delayed = 0;
    ngx_del_timer(c->write);
  }

  if (c->read->eof) {
    ngx_http_close_request(r, 0);
    return;
  }

  ngx_http_finalize_connection(r);
}


static void
ngx_http_terminate_request(ngx_http_request_t *r, ngx_int_t rc)
{
  ngx_http_cleanup_t    *cln;
  ngx_http_request_t    *mr;
  ngx_http_ephemeral_t  *e;

  mr = r->main;

  ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                 "http terminate request count:%d", mr->count);

  if (rc > 0 && (mr->headers_out.status == 0 || mr->connection->sent == 0)) {
    mr->headers_out.status = rc;
  }

  cln = mr->cleanup;
  mr->cleanup = NULL;

  while (cln) {
    if (cln->handler) {
      cln->handler(cln->data);
    }

    cln = cln->next;
  }

  ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                 "http terminate cleanup count:%d blk:%d",
                 mr->count, mr->blocked);

  if (mr->write_event_handler) {

    if (mr->blocked) {
      return;
    }

    e = ngx_http_ephemeral(mr);
    mr->posted_requests = NULL;
    mr->write_event_handler = ngx_http_terminate_handler;
    (void) ngx_http_post_request(mr, &e->terminal_posted_request);
    return;
  }

  ngx_http_close_request(mr, rc);
}


static void
ngx_http_terminate_handler(ngx_http_request_t *r)
{
  ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                 "http terminate handler count:%d", r->count);

  r->count = 1;

  ngx_http_close_request(r, 0);
}


static void
ngx_http_finalize_connection(ngx_http_request_t *r)
{
  ngx_http_core_loc_conf_t  *clcf;

  clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

  if (r->main->count != 1) {

    if (r->discard_body) {
      r->read_event_handler = ngx_http_discarded_request_body_handler;
      ngx_add_timer(r->connection->read, clcf->lingering_timeout);

      if (r->lingering_time == 0) {
        r->lingering_time = ngx_time()
            + (time_t) (clcf->lingering_time / 1000);
      }
    }

    ngx_http_close_request(r, 0);
    return;
  }

  if (!ngx_terminate
      && !ngx_exiting
      && r->keepalive
      && clcf->keepalive_timeout > 0)
  {
    ngx_http_set_keepalive(r);
    return;
  }

  if (clcf->lingering_close == NGX_HTTP_LINGERING_ALWAYS
      || (clcf->lingering_close == NGX_HTTP_LINGERING_ON
          && (r->lingering_close
              || r->header_in->pos < r->header_in->last
              || r->connection->read->ready)))
  {
    ngx_http_set_lingering_close(r);
    return;
  }

  ngx_http_close_request(r, 0);
}


static ngx_int_t
ngx_http_set_write_handler(ngx_http_request_t *r)
{
  ngx_event_t               *wev;
  ngx_http_core_loc_conf_t  *clcf;

  r->http_state = NGX_HTTP_WRITING_REQUEST_STATE;

  r->read_event_handler = r->discard_body ?
      ngx_http_discarded_request_body_handler:
      ngx_http_test_reading;
  r->write_event_handler = ngx_http_writer;

  wev = r->connection->write;

  if (wev->ready && wev->delayed) {
    return NGX_OK;
  }

  clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);
  if (!wev->delayed) {
    ngx_add_timer(wev, clcf->send_timeout);
  }

  if (ngx_handle_write_event(wev, clcf->send_lowat) != NGX_OK) {
    ngx_http_close_request(r, 0);
    return NGX_ERROR;
  }

  return NGX_OK;
}


static void
ngx_http_writer(ngx_http_request_t *r)
{
  int                        rc;
  ngx_event_t               *wev;
  ngx_connection_t          *c;
  ngx_http_core_loc_conf_t  *clcf;

  c = r->connection;
  wev = c->write;

  ngx_log_debug2(NGX_LOG_DEBUG_HTTP, wev->log, 0,
                 "http writer handler: \"%V?%V\"", &r->uri, &r->args);

  clcf = ngx_http_get_module_loc_conf(r->main, ngx_http_core_module);

  if (wev->timedout) {
    if (!wev->delayed) {
      ngx_log_error(NGX_LOG_INFO, c->log, NGX_ETIMEDOUT,
                    "client timed out");
      c->timedout = 1;

      ngx_http_finalize_request(r, NGX_HTTP_REQUEST_TIME_OUT);
      return;
    }

    wev->timedout = 0;
    wev->delayed = 0;

    if (!wev->ready) {
      ngx_add_timer(wev, clcf->send_timeout);

      if (ngx_handle_write_event(wev, clcf->send_lowat) != NGX_OK) {
        ngx_http_close_request(r, 0);
      }

      return;
    }

  }

  if (wev->delayed || r->aio) {
    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, wev->log, 0,
                   "http writer delayed");

    if (ngx_handle_write_event(wev, clcf->send_lowat) != NGX_OK) {
      ngx_http_close_request(r, 0);
    }

    return;
  }

  rc = ngx_http_output_filter(r, NULL);

  ngx_log_debug3(NGX_LOG_DEBUG_HTTP, c->log, 0,
                 "http writer output filter: %d, \"%V?%V\"",
                 rc, &r->uri, &r->args);

  if (rc == NGX_ERROR) {
    ngx_http_finalize_request(r, rc);
    return;
  }

  if (r->buffered || r->postponed || (r == r->main && c->buffered)) {

    if (!wev->delayed) {
      ngx_add_timer(wev, clcf->send_timeout);
    }

    if (ngx_handle_write_event(wev, clcf->send_lowat) != NGX_OK) {
      ngx_http_close_request(r, 0);
    }

    return;
  }

  ngx_log_debug2(NGX_LOG_DEBUG_HTTP, wev->log, 0,
                 "http writer done: \"%V?%V\"", &r->uri, &r->args);

  r->write_event_handler = ngx_http_request_empty_handler;

  ngx_http_finalize_request(r, rc);
}


static void
ngx_http_request_finalizer(ngx_http_request_t *r)
{
  ngx_log_debug2(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                 "http finalizer done: \"%V?%V\"", &r->uri, &r->args);

  ngx_http_finalize_request(r, 0);
}


void
ngx_http_block_reading(ngx_http_request_t *r)
{
  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                 "http reading blocked");

  /* aio does not call this handler */

  if ((ngx_event_flags & NGX_USE_LEVEL_EVENT)
      && r->connection->read->active)
  {
    if (ngx_del_event(r->connection->read, NGX_READ_EVENT, 0) != NGX_OK) {
      ngx_http_close_request(r, 0);
    }
  }
}


void
ngx_http_test_reading(ngx_http_request_t *r)
{
  int                n;
  char               buf[1];
  ngx_err_t          err;
  ngx_event_t       *rev;
  ngx_connection_t  *c;

  c = r->connection;
  rev = c->read;

  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "http test reading");

#if (NGX_HAVE_KQUEUE)

  if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {

    if (!rev->pending_eof) {
      return;
    }

    rev->eof = 1;
    c->error = 1;
    err = rev->kq_errno;

    goto closed;
  }

#endif

  n = recv(c->fd, buf, 1, MSG_PEEK);

  if (n == 0) {
    rev->eof = 1;
    c->error = 1;
    err = 0;

    goto closed;

  } else if (n == -1) {
    err = ngx_socket_errno;

    if (err != NGX_EAGAIN) {
      rev->eof = 1;
      c->error = 1;

      goto closed;
    }
  }

  /* aio does not call this handler */

  if ((ngx_event_flags & NGX_USE_LEVEL_EVENT) && rev->active) {

    if (ngx_del_event(rev, NGX_READ_EVENT, 0) != NGX_OK) {
      ngx_http_close_request(r, 0);
    }
  }

  return;

closed:

  if (err) {
    rev->error = 1;
  }

  ngx_log_error(NGX_LOG_INFO, c->log, err,
                "client closed prematurely connection");

  ngx_http_finalize_request(r, 0);
}


static void
ngx_http_set_keepalive(ngx_http_request_t *r)
{
  int                        tcp_nodelay;
  ngx_int_t                  i;
  ngx_buf_t                 *b, *f;
  ngx_event_t               *rev, *wev;
  ngx_connection_t          *c;
  ngx_http_connection_t     *hc;
  ngx_http_core_srv_conf_t  *cscf;
  ngx_http_core_loc_conf_t  *clcf;

  c = r->connection;
  rev = c->read;

  clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "set http keepalive handler");

  if (r->discard_body) {
    r->write_event_handler = ngx_http_request_empty_handler;
    r->lingering_time = ngx_time() + (time_t) (clcf->lingering_time / 1000);
    ngx_add_timer(rev, clcf->lingering_timeout);
    return;
  }

  c->log->action = "closing request";

  hc = r->http_connection;
  b = r->header_in;

  if (b->pos < b->last) {

    /* the pipelined request */

    if (b != c->buffer) {

      /*
       * If the large header buffers were allocated while the previous
       * request processing then we do not use c->buffer for
       * the pipelined request (see ngx_http_init_request()).
       *
       * Now we would move the large header buffers to the free list.
       */

      cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);

      if (hc->free == NULL) {
        hc->free = ngx_palloc(c->pool,
                              cscf->large_client_header_buffers.num * sizeof(ngx_buf_t *));

        if (hc->free == NULL) {
          ngx_http_close_request(r, 0);
          return;
        }
      }

      for (i = 0; i < hc->nbusy - 1; i++) {
        f = hc->busy[i];
        hc->free[hc->nfree++] = f;
        f->pos = f->start;
        f->last = f->start;
      }

      hc->busy[0] = b;
      hc->nbusy = 1;
    }
  }

  r->keepalive = 0;

  ngx_http_free_request(r, 0);

  c->data = hc;

  ngx_add_timer(rev, clcf->keepalive_timeout);

  if (ngx_handle_read_event(rev, 0) != NGX_OK) {
    ngx_http_close_connection(c);
    return;
  }

  wev = c->write;
  wev->handler = ngx_http_empty_handler;

  if (b->pos < b->last) {

    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "pipelined request");

#if (NGX_STAT_STUB)
    (void) ngx_atomic_fetch_add(ngx_stat_reading, 1);
#endif

    hc->pipeline = 1;
    c->log->action = "reading client pipelined request line";

    rev->handler = ngx_http_init_request;
    ngx_post_event(rev, &ngx_posted_events);
    return;
  }

  hc->pipeline = 0;

  /*
   * To keep a memory footprint as small as possible for an idle
   * keepalive connection we try to free the ngx_http_request_t and
   * c->buffer's memory if they were allocated outside the c->pool.
   * The large header buffers are always allocated outside the c->pool and
   * are freed too.
   */

  if (ngx_pfree(c->pool, r) == NGX_OK) {
    hc->request = NULL;
  }

  b = c->buffer;

  if (ngx_pfree(c->pool, b->start) == NGX_OK) {

    /*
     * the special note for ngx_http_keepalive_handler() that
     * c->buffer's memory was freed
     */

    b->pos = NULL;

  } else {
    b->pos = b->start;
    b->last = b->start;
  }

  ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0, "hc free: %p %d",
                 hc->free, hc->nfree);

  if (hc->free) {
    for (i = 0; i < hc->nfree; i++) {
      ngx_pfree(c->pool, hc->free[i]->start);
      hc->free[i] = NULL;
    }

    hc->nfree = 0;
  }

  ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0, "hc busy: %p %d",
                 hc->busy, hc->nbusy);

  if (hc->busy) {
    for (i = 0; i < hc->nbusy; i++) {
      ngx_pfree(c->pool, hc->busy[i]->start);
      hc->busy[i] = NULL;
    }

    hc->nbusy = 0;
  }

#if (NGX_HTTP_SSL)
  if (c->ssl) {
    ngx_ssl_free_buffer(c);
  }
#endif

  rev->handler = ngx_http_keepalive_handler;

  if (wev->active && (ngx_event_flags & NGX_USE_LEVEL_EVENT)) {
    if (ngx_del_event(wev, NGX_WRITE_EVENT, 0) != NGX_OK) {
      ngx_http_close_connection(c);
      return;
    }
  }

  c->log->action = "keepalive";

  if (c->tcp_nopush == NGX_TCP_NOPUSH_SET) {
    if (ngx_tcp_push(c->fd) == -1) {
      ngx_connection_error(c, ngx_socket_errno, ngx_tcp_push_n " failed");
      ngx_http_close_connection(c);
      return;
    }

    c->tcp_nopush = NGX_TCP_NOPUSH_UNSET;
    tcp_nodelay = ngx_tcp_nodelay_and_tcp_nopush ? 1 : 0;

  } else {
    tcp_nodelay = 1;
  }

  if (tcp_nodelay
      && clcf->tcp_nodelay
      && c->tcp_nodelay == NGX_TCP_NODELAY_UNSET)
  {
    ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "tcp_nodelay");

    if (setsockopt(c->fd, IPPROTO_TCP, TCP_NODELAY,
                   (const void *) &tcp_nodelay, sizeof(int))
        == -1)
    {
#if (NGX_SOLARIS)
      /* Solaris returns EINVAL if a socket has been shut down */
      c->log_error = NGX_ERROR_IGNORE_EINVAL;
#endif

      ngx_connection_error(c, ngx_socket_errno,
                           "setsockopt(TCP_NODELAY) failed");

      c->log_error = NGX_ERROR_INFO;
      ngx_http_close_connection(c);
      return;
    }

    c->tcp_nodelay = NGX_TCP_NODELAY_SET;
  }

#if 0
  /* if ngx_http_request_t was freed then we need some other place */
  r->http_state = NGX_HTTP_KEEPALIVE_STATE;
#endif

  c->idle = 1;
  ngx_reusable_connection(c, 1);

  if (rev->ready) {
    ngx_post_event(rev, &ngx_posted_events);
  }
}


static void
ngx_http_keepalive_handler(ngx_event_t *rev)
{
  size_t             size;
  ssize_t            n;
  ngx_buf_t         *b;
  ngx_connection_t  *c;

  c = rev->data;

  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0, "http keepalive handler");

  if (rev->timedout || c->close) {
    ngx_http_close_connection(c);
    return;
  }

#if (NGX_HAVE_KQUEUE)

  if (ngx_event_flags & NGX_USE_KQUEUE_EVENT) {
    if (rev->pending_eof) {
      c->log->handler = NULL;
      ngx_log_error(NGX_LOG_INFO, c->log, rev->kq_errno,
                    "kevent() reported that client %V closed "
                    "keepalive connection", &c->addr_text);
#if (NGX_HTTP_SSL)
      if (c->ssl) {
        c->ssl->no_send_shutdown = 1;
      }
#endif
      ngx_http_close_connection(c);
      return;
    }
  }

#endif

  b = c->buffer;
  size = b->end - b->start;

  if (b->pos == NULL) {

    /*
     * The c->buffer's memory was freed by ngx_http_set_keepalive().
     * However, the c->buffer->start and c->buffer->end were not changed
     * to keep the buffer size.
     */

    b->pos = ngx_palloc(c->pool, size);
    if (b->pos == NULL) {
      ngx_http_close_connection(c);
      return;
    }

    b->start = b->pos;
    b->last = b->pos;
    b->end = b->pos + size;
  }

  /*
   * MSIE closes a keepalive connection with RST flag
   * so we ignore ECONNRESET here.
   */

  c->log_error = NGX_ERROR_IGNORE_ECONNRESET;
  ngx_set_socket_errno(0);

  n = c->recv(c, b->last, size);
  c->log_error = NGX_ERROR_INFO;

  if (n == NGX_AGAIN) {
    if (ngx_handle_read_event(rev, 0) != NGX_OK) {
      ngx_http_close_connection(c);
    }

    return;
  }

  if (n == NGX_ERROR) {
    ngx_http_close_connection(c);
    return;
  }

  c->log->handler = NULL;

  if (n == 0) {
    ngx_log_error(NGX_LOG_INFO, c->log, ngx_socket_errno,
                  "client %V closed keepalive connection", &c->addr_text);
    ngx_http_close_connection(c);
    return;
  }

  b->last += n;

#if (NGX_STAT_STUB)
  (void) ngx_atomic_fetch_add(ngx_stat_reading, 1);
#endif

  c->log->handler = ngx_http_log_error;
  c->log->action = "reading client request line";

  c->idle = 0;
  ngx_reusable_connection(c, 0);

  ngx_http_init_request(rev);
}


static void
ngx_http_set_lingering_close(ngx_http_request_t *r)
{
  ngx_event_t               *rev, *wev;
  ngx_connection_t          *c;
  ngx_http_core_loc_conf_t  *clcf;

  c = r->connection;

  clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

  rev = c->read;
  rev->handler = ngx_http_lingering_close_handler;

  r->lingering_time = ngx_time() + (time_t) (clcf->lingering_time / 1000);
  ngx_add_timer(rev, clcf->lingering_timeout);

  if (ngx_handle_read_event(rev, 0) != NGX_OK) {
    ngx_http_close_request(r, 0);
    return;
  }

  wev = c->write;
  wev->handler = ngx_http_empty_handler;

  if (wev->active && (ngx_event_flags & NGX_USE_LEVEL_EVENT)) {
    if (ngx_del_event(wev, NGX_WRITE_EVENT, 0) != NGX_OK) {
      ngx_http_close_request(r, 0);
      return;
    }
  }

  if (ngx_shutdown_socket(c->fd, NGX_WRITE_SHUTDOWN) == -1) {
    ngx_connection_error(c, ngx_socket_errno,
                         ngx_shutdown_socket_n " failed");
    ngx_http_close_request(r, 0);
    return;
  }

  if (rev->ready) {
    ngx_http_lingering_close_handler(rev);
  }
}


static void
ngx_http_lingering_close_handler(ngx_event_t *rev)
{
  ssize_t                    n;
  ngx_msec_t                 timer;
  ngx_connection_t          *c;
  ngx_http_request_t        *r;
  ngx_http_core_loc_conf_t  *clcf;
  u_char                     buffer[NGX_HTTP_LINGERING_BUFFER_SIZE];

  c = rev->data;
  r = c->data;

  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, c->log, 0,
                 "http lingering close handler");

  if (rev->timedout) {
    ngx_http_close_request(r, 0);
    return;
  }

  timer = (ngx_msec_t) (r->lingering_time - ngx_time());
  if (timer <= 0) {
    ngx_http_close_request(r, 0);
    return;
  }

  do {
    n = c->recv(c, buffer, NGX_HTTP_LINGERING_BUFFER_SIZE);

    ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0, "lingering read: %d", n);

    if (n == NGX_ERROR || n == 0) {
      ngx_http_close_request(r, 0);
      return;
    }

  } while (rev->ready);

  if (ngx_handle_read_event(rev, 0) != NGX_OK) {
    ngx_http_close_request(r, 0);
    return;
  }

  clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

  timer *= 1000;

  if (timer > clcf->lingering_timeout) {
    timer = clcf->lingering_timeout;
  }

  ngx_add_timer(rev, timer);
}


void
ngx_http_empty_handler(ngx_event_t *wev)
{
  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, wev->log, 0, "http empty handler");

  return;
}


void
ngx_http_request_empty_handler(ngx_http_request_t *r)
{
  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                 "http request empty handler");

  return;
}


ngx_int_t
ngx_http_send_special(ngx_http_request_t *r, ngx_uint_t flags)
{
  ngx_buf_t    *b;
  ngx_chain_t   out;

  b = ngx_calloc_buf(r->pool);
  if (b == NULL) {
    return NGX_ERROR;
  }

  if (flags & NGX_HTTP_LAST) {

    if (r == r->main && !r->post_action) {
      b->last_buf = 1;

    } else {
      b->sync = 1;
      b->last_in_chain = 1;
    }
  }

  if (flags & NGX_HTTP_FLUSH) {
    b->flush = 1;
  }

  out.buf = b;
  out.next = NULL;

  return ngx_http_output_filter(r, &out);
}


static ngx_int_t
ngx_http_post_action(ngx_http_request_t *r)
{
  ngx_http_core_loc_conf_t  *clcf;

  clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

  if (clcf->post_action.data == NULL) {
    return NGX_DECLINED;
  }

  if (r->post_action && r->uri_changes == 0) {
    return NGX_DECLINED;
  }

  ngx_log_debug1(NGX_LOG_DEBUG_HTTP, r->connection->log, 0,
                 "post action: \"%V\"", &clcf->post_action);

  r->main->count--;

  r->http_version = NGX_HTTP_VERSION_9;
  r->header_only = 1;
  r->post_action = 1;

  r->read_event_handler = ngx_http_block_reading;

  if (clcf->post_action.data[0] == '/') {
    ngx_http_internal_redirect(r, &clcf->post_action, NULL);

  } else {
    ngx_http_named_location(r, &clcf->post_action);
  }

  return NGX_OK;
}


static void
ngx_http_close_request(ngx_http_request_t *r, ngx_int_t rc)
{
  ngx_connection_t  *c;

  r = r->main;
  c = r->connection;

  ngx_log_debug2(NGX_LOG_DEBUG_HTTP, c->log, 0,
                 "http request count:%d blk:%d", r->count, r->blocked);

  if (r->count == 0) {
    ngx_log_error(NGX_LOG_ALERT, c->log, 0, "http request count is zero");
  }

  r->count--;

  if (r->count || r->blocked) {
    return;
  }

  ngx_http_free_request(r, rc);
  ngx_http_close_connection(c);
}


static void
ngx_http_free_request(ngx_http_request_t *r, ngx_int_t rc)
{
  ngx_log_t                 *log;
  struct linger              linger;
  ngx_http_cleanup_t        *cln;
  ngx_http_log_ctx_t        *ctx;
  ngx_http_core_loc_conf_t  *clcf;

  log = r->connection->log;

  ngx_log_debug0(NGX_LOG_DEBUG_HTTP, log, 0, "http close request");

  if (r->pool == NULL) {
    ngx_log_error(NGX_LOG_ALERT, log, 0, "http request already closed");
    return;
  }

  for (cln = r->cleanup; cln; cln = cln->next) {
    if (cln->handler) {
      cln->handler(cln->data);
    }
  }

#if (NGX_STAT_STUB)

  if (r->stat_reading) {
    (void) ngx_atomic_fetch_add(ngx_stat_reading, -1);
  }

  if (r->stat_writing) {
    (void) ngx_atomic_fetch_add(ngx_stat_writing, -1);
  }

#endif

  if (rc > 0 && (r->headers_out.status == 0 || r->connection->sent == 0)) {
    r->headers_out.status = rc;
  }

  log->action = "logging request";

  ngx_http_log_request(r);

  log->action = "closing request";

  if (r->connection->timedout) {
    clcf = ngx_http_get_module_loc_conf(r, ngx_http_core_module);

    if (clcf->reset_timedout_connection) {
      linger.l_onoff = 1;
      linger.l_linger = 0;

      if (setsockopt(r->connection->fd, SOL_SOCKET, SO_LINGER,
                     (const void *) &linger, sizeof(struct linger)) == -1)
      {
        ngx_log_error(NGX_LOG_ALERT, log, ngx_socket_errno,
                      "setsockopt(SO_LINGER) failed");
      }
    }
  }

  /* the various request strings were allocated from r->pool */
  ctx = log->data;
  ctx->request = NULL;

  r->request_line.len = 0;

  r->connection->destroyed = 1;

  ngx_destroy_pool(r->pool);
}


static void
ngx_http_log_request(ngx_http_request_t *r)
{
  ngx_uint_t                  i, n;
  ngx_http_handler_pt        *log_handler;
  ngx_http_core_main_conf_t  *cmcf;

  cmcf = ngx_http_get_module_main_conf(r, ngx_http_core_module);

  log_handler = cmcf->phases[NGX_HTTP_LOG_PHASE].handlers.elts;
  n = cmcf->phases[NGX_HTTP_LOG_PHASE].handlers.nelts;

  for (i = 0; i < n; i++) {
    log_handler[i](r);
  }
}


static void
ngx_http_close_connection(ngx_connection_t *c)
{
  ngx_pool_t  *pool;

  ngx_log_debug1(NGX_LOG_DEBUG_HTTP, c->log, 0,
                 "close http connection: %d", c->fd);

#if (NGX_HTTP_SSL)

  if (c->ssl) {
    if (ngx_ssl_shutdown(c) == NGX_AGAIN) {
      c->ssl->handler = ngx_http_close_connection;
      return;
    }
  }

#endif

#if (NGX_STAT_STUB)
  (void) ngx_atomic_fetch_add(ngx_stat_active, -1);
#endif

  c->destroyed = 1;

  pool = c->pool;

  ngx_close_connection(c);

  ngx_destroy_pool(pool);
}


static u_char *
ngx_http_log_error(ngx_log_t *log, u_char *buf, size_t len)
{
  u_char              *p;
  ngx_http_request_t  *r;
  ngx_http_log_ctx_t  *ctx;

  if (log->action) {
    p = ngx_snprintf(buf, len, " while %s", log->action);
    len -= p - buf;
    buf = p;
  }

  ctx = log->data;

  p = ngx_snprintf(buf, len, ", client: %V", &ctx->connection->addr_text);
  len -= p - buf;

  r = ctx->request;

  if (r) {
    return r->log_handler(r, ctx->current_request, p, len);

  } else {
    p = ngx_snprintf(p, len, ", server: %V",
                     &ctx->connection->listening->addr_text);
  }

  return p;
}


static u_char *
ngx_http_log_error_handler(ngx_http_request_t *r, ngx_http_request_t *sr,
                           u_char *buf, size_t len)
{
  char                      *uri_separator;
  u_char                    *p;
  ngx_http_upstream_t       *u;
  ngx_http_core_srv_conf_t  *cscf;

  cscf = ngx_http_get_module_srv_conf(r, ngx_http_core_module);

  p = ngx_snprintf(buf, len, ", server: %V", &cscf->server_name);
  len -= p - buf;
  buf = p;

  if (r->request_line.data == NULL && r->request_start) {
    for (p = r->request_start; p < r->header_in->last; p++) {
      if (*p == CR || *p == LF) {
        break;
      }
    }

    r->request_line.len = p - r->request_start;
    r->request_line.data = r->request_start;
  }

  if (r->request_line.len) {
    p = ngx_snprintf(buf, len, ", request: \"%V\"", &r->request_line);
    len -= p - buf;
    buf = p;
  }

  if (r != sr) {
    p = ngx_snprintf(buf, len, ", subrequest: \"%V\"", &sr->uri);
    len -= p - buf;
    buf = p;
  }

  u = sr->upstream;

  if (u && u->peer.name) {

    uri_separator = "";

#if (NGX_HAVE_UNIX_DOMAIN)
    if (u->peer.sockaddr && u->peer.sockaddr->sa_family == AF_UNIX) {
      uri_separator = ":";
    }
#endif

    p = ngx_snprintf(buf, len, ", upstream: \"%V%V%s%V\"",
                     &u->schema, u->peer.name,
                     uri_separator, &u->uri);
    len -= p - buf;
    buf = p;
  }

  if (r->headers_in.host) {
    p = ngx_snprintf(buf, len, ", host: \"%V\"",
                     &r->headers_in.host->value);
    len -= p - buf;
    buf = p;
  }

  if (r->headers_in.referer) {
    p = ngx_snprintf(buf, len, ", referrer: \"%V\"",
                     &r->headers_in.referer->value);
    buf = p;
  }

  return buf;
}
